TY - JOUR
T1 - Weight loss after Roux-En-Y gastric bypass surgery reveals skeletal muscle DNA methylation changes
AU - Garcia, Luis A.
AU - Day, Samantha E.
AU - Coletta, Richard L.
AU - Campos, Baltazar
AU - Benjamin, Tonya R.
AU - De Filippis, Eleanna
AU - Madura, James A.
AU - Mandarino, Lawrence J.
AU - Roust, Lori R.
AU - Coletta, Dawn K.
N1 - Funding Information:
This study was supported by the National Institutes of Health Grants R01DK094013 (DKC) and a Mayo/ASU seed grant (DKC, LRR).
Funding Information:
We thank the volunteers of the study and are grateful for their participation and cooperation. We thank the Clinical Studies Infusion Unit nurses and research staff for their excellent care of the participants. We thank the Mayo Clinic Genotyping Shared Resource facility for the RRBS next generation methylation analysis.
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - Background: The mechanisms of weight loss and metabolic improvements following bariatric surgery in skeletal muscle are not well known; however, epigenetic modifications are likely to contribute. The aim of our study was to investigate skeletal muscle DNA methylation after weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Muscle biopsies were obtained basally from seven insulin-resistant obese (BMI > 40 kg/m2) female subjects (45.1 ± 3.6 years) pre- and 3-month post-surgery with euglycemic hyperinsulinemic clamps to assess insulin sensitivity. Four lean (BMI < 25 kg/m2) females (38.5 ± 5.8 years) served as controls. We performed reduced representation bisulfite sequencing next generation methylation on DNA isolated from the vastus lateralis muscle biopsies. Results: Global methylation was significantly higher in the pre- (32.97 ± 0.02%) and post-surgery (33.31 ± 0.02%) compared to the lean (30.46 ± 0.02%), P < 0.05. MethylSig analysis identified 117 differentially methylated cytosines (DMCs) that were significantly altered in the post- versus pre-surgery (Benjamini–Hochberg q < 0.05). In addition, 2978 DMCs were significantly altered in the pre-surgery obese versus the lean controls (Benjamini–Hochberg q < 0.05). For the post-surgery obese versus the lean controls, 2885 DMCs were altered (Benjamini–Hochberg q < 0.05). Seven post-surgery obese DMCs were normalized to levels similar to those observed in lean controls. Of these, 5 were within intergenic regions (chr11.68,968,018, chr16.73,100,688, chr5.174,115,531, chr5.1,831,958 and chr9.98,547,011) and the remaining two DMCs chr17.45,330,989 and chr14.105,353,824 were within in the integrin beta 3 (ITGB3) promoter and KIAA0284 exon, respectively. ITGB3 methylation was significantly decreased in the post-surgery (0.5 ± 0.5%) and lean controls (0 ± 0%) versus pre-surgery (13.6 ± 2.7%, P < 0.05). This decreased methylation post-surgery was associated with an increase in ITGB3 gene expression (fold change + 1.52, P = 0.0087). In addition, we showed that ITGB3 promoter methylation in vitro significantly suppressed transcriptional activity (P < 0.05). Transcription factor binding analysis for ITGB3 chr17.45,330,989 identified three putative transcription factor binding motifs; PAX-5, p53 and AP-2alphaA. Conclusions: These results demonstrate that weight loss after RYGB alters the epigenome through DNA methylation. In particular, this study highlights ITGB3 as a novel gene that may contribute to the metabolic improvements observed post-surgery. Future additional studies are warranted to address the exact mechanism of ITGB3 in skeletal muscle.
AB - Background: The mechanisms of weight loss and metabolic improvements following bariatric surgery in skeletal muscle are not well known; however, epigenetic modifications are likely to contribute. The aim of our study was to investigate skeletal muscle DNA methylation after weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Muscle biopsies were obtained basally from seven insulin-resistant obese (BMI > 40 kg/m2) female subjects (45.1 ± 3.6 years) pre- and 3-month post-surgery with euglycemic hyperinsulinemic clamps to assess insulin sensitivity. Four lean (BMI < 25 kg/m2) females (38.5 ± 5.8 years) served as controls. We performed reduced representation bisulfite sequencing next generation methylation on DNA isolated from the vastus lateralis muscle biopsies. Results: Global methylation was significantly higher in the pre- (32.97 ± 0.02%) and post-surgery (33.31 ± 0.02%) compared to the lean (30.46 ± 0.02%), P < 0.05. MethylSig analysis identified 117 differentially methylated cytosines (DMCs) that were significantly altered in the post- versus pre-surgery (Benjamini–Hochberg q < 0.05). In addition, 2978 DMCs were significantly altered in the pre-surgery obese versus the lean controls (Benjamini–Hochberg q < 0.05). For the post-surgery obese versus the lean controls, 2885 DMCs were altered (Benjamini–Hochberg q < 0.05). Seven post-surgery obese DMCs were normalized to levels similar to those observed in lean controls. Of these, 5 were within intergenic regions (chr11.68,968,018, chr16.73,100,688, chr5.174,115,531, chr5.1,831,958 and chr9.98,547,011) and the remaining two DMCs chr17.45,330,989 and chr14.105,353,824 were within in the integrin beta 3 (ITGB3) promoter and KIAA0284 exon, respectively. ITGB3 methylation was significantly decreased in the post-surgery (0.5 ± 0.5%) and lean controls (0 ± 0%) versus pre-surgery (13.6 ± 2.7%, P < 0.05). This decreased methylation post-surgery was associated with an increase in ITGB3 gene expression (fold change + 1.52, P = 0.0087). In addition, we showed that ITGB3 promoter methylation in vitro significantly suppressed transcriptional activity (P < 0.05). Transcription factor binding analysis for ITGB3 chr17.45,330,989 identified three putative transcription factor binding motifs; PAX-5, p53 and AP-2alphaA. Conclusions: These results demonstrate that weight loss after RYGB alters the epigenome through DNA methylation. In particular, this study highlights ITGB3 as a novel gene that may contribute to the metabolic improvements observed post-surgery. Future additional studies are warranted to address the exact mechanism of ITGB3 in skeletal muscle.
KW - Bariatric surgery
KW - DNA methylation
KW - Next generation sequencing
KW - Obesity
KW - Skeletal muscle
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U2 - 10.1186/s13148-021-01086-6
DO - 10.1186/s13148-021-01086-6
M3 - Article
C2 - 33933146
AN - SCOPUS:85105003771
SN - 1868-7075
VL - 13
JO - Clinical Epigenetics
JF - Clinical Epigenetics
IS - 1
M1 - 100
ER -